Process for obtaining the relief or clearance angle in circular edge cutting



E. J. WEBER Sept. 16, 1969 3,466,909 PROCESS FOR OBTAINING THE RELIEF OR CLEARANCE ANGLE IN CIRCULAR EDGE CUTTING 3 Sheets-Sheet 1 Filed Aug. 16, 1967 "I Kcrzest'a k flaier BY Mid 1 TNVENT OR ATTORNEY Sept. 16, 1969 E. .1. WE 5 3,466,909

PROCESS FOR OBTAINING THE RELIEF OR CLEARANCE ANGLE IN CIRCULAR EDGE CUTTING Filed Aug. 16, 1967 5 Sheets-Sheet 2 ATTORNEY E. J. WEBER Sept. 16,1969

PROCESS FOR OBTAINING THE RELIEF OR CLEARANCE ANGLE IN CIRCULAR EDGE CUTTING 3 Sheets-Sheet 5 Filed Aug. 16, 1967 INVENT OR ATTORNEY United States Patent 3,466,909 PROCESS FOR OBTAINING THE RELIEF OR CLEARANCE ANGLE IN CIRCULAR EDGE CUTTING Ernesto J. Weber, Lluvia 470, Mexico City 20, Mexico Continuation-impart of application Ser. No. 504,258, Oct. 23, 1965. This application Aug. 16, 1967, Ser. No. 661,131

Int. Cl. B21b 15/00, 23/00; 132111 22/ 003 US. CI. 72-68 Claims ABSTRACT OF THE DISCLOSURE The subject application is a continuation-in-part of application, Ser. No. 504,258, filed Oct. 23, 1965, now abandoned.

This invention relates to an apparatus and method for simultaneously bending teeth edge trimmers or cutters to obtain requisite relief angles or clearances in circular edge cutters for shoe soles and the like, utilizing an inexpensive, easily operated and very rapid mechanical arrangement as compared with relatively slow and expensive conventional relieving machines.'

One of the objects of my invention is the provision of a simplified process for obtaining relief or clearance angles in circular edge cutters used in connection with the manufacture of shoe soles.

Another object resides in the provision of a process of simultaneously bending back the individual teeth in a selected blank, causing the land of each tooth, as viewed along the axis of the blank to be displaced to a position in which the land forms a designated clearance or relief angle tangential to the outermost circle.

FIGURE 1 is a perspective view of the machine used to effect bending of the teeth to provide relief or clearance angles.

FIGURE 2 is a top plan view of a blank before subjection to the subject process and apparatus.

FIGURE 3 is a diametrical sectional view taken on the lines 3-3 of FIGURE 2.

FIGURE 4 is a fragmentary detail view of the teeth of the blank before and after bending, while FIGURE 5 is another detailed view showing the material to be machined off in the conventional method for obtaining relief angle, commonly known as relieving.

In the drawings where like reference characters denote like parts, the numeral refers to the standard or support mounted on the base 12. A bender 14 having a plurality of teeth grooves 16 is also mounted on this base 12.

A piston 18, mounted on the standard 10, is keyed into depending cylinder 20 by the key 22 and as a result cannot turn. A blank 24 having a collar 26 and a plurality of teeth 28 has been shown vertically positioned above the bender 14.

It is to be observed that the teeth 28 of the blank 24 is adapted to fit exactly in the grooves 16 of the bender 14. It is also to be understood that the piston 18 may be mechanically or hydraulically lowered to push the blank "ice 24 into the bender 14 to effect bending of the teeth 28 of the blank 24. Further, it is to be appreciated that the blank 24 must have been previously heated in an oven or other means to a red hot temperature. An oil valve 25 has been indicated in this view.

As the piston 18 is lowered, it forces the blank 24 into the bender 14 and it is to be noticed that the piston 18 has been fluted at 30 and is provided with a guide nose 32, said guide nose being adapted to be received in the knob 34 in the base of the bender 14. In addition, it is to be noticed that the outside diameter of the fluted section 30 is slightly in excess of the diameter of the center bore 36 of the blank 24 and this fluted section 30 will penetrate the blank once it has been seated on the knob and forced downwardly. When the piston has been completely lowered, the blank 24 cannot turn around in that its axis is held securely in place by piston 18 and its fluted section 30.

While the blank 24 is still hot, the bender 14 is rotated through an angle suflicient to bend the teeth of the blank 24 to the desired point to obtain the result indicated in FIGURE 4.

With reference to FIGURE 2, a blank 24 has been shown before being subjected to the instant process and adapted to be mounted in position relative to the pieces or teeth 16 which, when rotated simultaneously in direction 36, will bend back all of the teeth 28. The blank 24, shown in this and other views, is comparable to blanks before being subjected to conventional relieving operation in this field.

FIGURE 3 shows an enlarged vertical sectional view of the blank 24 taken on the line 3-3 of FIGURE 2.

FIGURE 4 is a fragmentary detail view showing the teeth 28 of the blank 24 before bending in dotted lines 24 and after bending in continuous or solid lines, resulting in the relief angle 40.

As stated above, the subject apparatus and method is used to obtain the requisite relief or clearance angles, indispensable in acquiring the cutting effect in circular edge cutters relative to shoe soles. The blank 24, as shown in FIGURE 2, represents that used in the process and is made from steel by means of conventional mechanical turning and milling operations.

The assembly of teeth 16 of the bender 14, as shown in FIGURES l and 2, is rigidly mounted on forms or an integral part of a, suitable holding base 12 which can be made to concentrically turn with respect to the longitudinal axis of blank 24, rotating in direction 50 with respect to said blank.

Between the pushing faces 15 of the pieces or teeth 16 of the bender 14 and the said blank there are slight angles 54 to prevent spoiling of the cutting edges 52. Upon rotation of the assembly pieces 16 with respect to the blank 24 all teeth in said blank are simultaneously bent, bending by deformation around the neck 56.

As stated above, FIGURE 4 shows in detail the position of each tooth 28 in dotted lines before bending and their relative positions after bending in solid lines. The magnitude of this displacement should be sufficient to obtain the required angle 40 which results precisely in the desired clearance or relief angle as shown in FIGURE 4.

The dimensions of blank 24 should be such that after bending, the requisite configuration is obtained. This can be accomplished by means of conventional mechanical design procedures. As shown in FIGURE 3, the sectional view represents one of the many possible cutting profiles and the profile of the edge of the average shoe is a good example.

It is to be appreciated that the bending effect on the teeth should be carried out at a temperature of the blank 24 such that weakening neck 56 of the teeth is prevented and, of course, this temperature is predicated upon the steel that is used. The subject process has been applied experimentally and has resulted in perfectly finished edge cutters or trimmers.

In the past, with specific reference to the old type of edge cutters, the method previously known as relieving had been universally used to obtain a relief or clearance angle, as shown in FIG. 5. Although the outside diameter of the edge cutters for the shoe soles in question is variable, it is usually 1.8 to 1.9 inches in diameter, and 0.75 to 0.85 inch full length along the axis, with the profile 58, as shown in FIGURE 3, from a few tenths of an inch wide to a width comparable to the full length of the cutter.

It is to be understood that the above described apparatus and method is only illustrative of the invention and numerous other arrangements might readily be devised by those skilled in the art without departing from the spirit or scope of the appended claims.

I claim:

1. In an apparatus for simultaneously bending all teeth in a suitably designed blank, a support and a bender located in the lower portion thereof, a knob positioned in the lower portion of said bender centrally thereof, a fluted piston centrally mounted in the upper portion of said support directly above said bender, said piston being provided with a guide nose adapted to be received in the knob in the base of said bender, a plurality of teeth grooves formed in said bender, and said blank having a plurality of teeth adapted to fit exactly in the grooves of said bender when said piston is lowered to force said blank into the grooves of said bender whereby when said blank is rotated clockwise the teeth in said blank will be bent back.

2. In an apparatus for simultaneously bending all teeth in a suitably designed blank, a support and a bender located in the lower portion thereof, a knob positioned in the lower portion of said bender centrally thereof, a fluted piston centrally mounted in the upper portion of said support directly above said bender, the outer diameter of said fluted piston being slightly in excess of that of the central bore of said blank, said piston being provided With a guide nose adapted to be received in the knob in the base of said bender, a plurality of teeth grooves formed in said bender, and said blank having a plurality of teeth adapted to fit exactly in the grooves of said bender when said piston is lowered to force said blank into the grooves of said bender.

3. In an apparatus for simultaneously bending all teeth in a suitably designed blank, a support and a bender located in the lower portion thereof, a knob positioned in the lower portion of said bender centrally thereof, a fluted piston centrally mounted in the upper portion of said support directly above said bender whereby the turning of said blank is precluded due to being securely held in place by the positioning of said fluted portion of said piston in the knob of said bender, said piston being provided with a guide nose adapted to be received in the knob in the base of said bender, a plurality of teeth grooves formed in said bender, and said blank having a plurality of teeth adapted to fit exactly in the grooves of said bender when said piston is hydraulically lowered to force said blank into the grooves of said bender whereby when said blank is rotated clockwise the teeth in said blank will be bent back.

References Cited UNITED STATES PATENTS 387,471 8/1888 Weeden 29-1 78 551,064 12/1895 Tyler 76-l01 1,784,745 12/ 1930 Nier 7268 2,978,797 4/ 1961 Ekelund 29-1573 RICHARD J. HERBST, Primary Examiner US. Cl. X.R. 

